The first deploy failed its wait. The app was up -- Rocket had launched on port
80 and systemd reported the unit active -- but `podman healthcheck run` kept
returning non-zero. Podman's healthcheck plumbing is unreliable for
Quadlet-managed rootless containers: the check is registered against the *user*
systemd manager, and when that fails the check never runs, leaving `podman
healthcheck run` to report that the container has no healthcheck at all even
though the image declares one (upstream issues #26066, #25034, #22804).
Exec the image's own /healthcheck.sh instead: the identical probe (curl
http://localhost:80/alive) with no plumbing in between, and still nothing the
play has to invent. The cost is that the path is hardcoded, which the image's
Dockerfile pins, so a moved script fails as a plain 127 rather than hanging.
The wait is now a block with a rescue that prints the probe's own stdout/stderr,
the container's health status and the last 20 log lines. The bare "non-zero
return code" the plain task reported is exactly the message that hides the
reason.
The readme's verification commands and a new gotcha record why the probe is
exec'd, so nobody "fixes" it back to `podman healthcheck run`.
tanshu
17c64cf2f8